In the bread-making process it is known to add bread-improving additives and/or dough conditioners to the bread dough, the action of which, inter alia, results in improved texture, volume, flavour and freshness of the bread as well as improved machinability of the dough.
In recent years enzymes have been found to be useful as dough conditioners and/or bread-improving agents, in particular enzymes such as amylases and proteases which act on components present in large amounts in the dough.
Lipase (EC 3.1.1.3) is an enzyme belonging to the glycerol ester hydrolases, which catalyzes hydrolysis of ester bonds in triglycerides. The use of lipases in the preparation of bread has been suggested for smoothening and thereby improving the texture of bread, but it has been concluded that when lipase is used alone other properties of the bread such as bread volume, elasticity of the crumb and mouth-feel are deteriorated (JP-A 62-285749). In fact, the use of lipase in the baking industry has been stated as undesirable (Gams, 1976).
JP-A 62-285749 discloses a method of making bread, in which lipase is added to dough in admixture with vital gluten and lecithin. By the addition of vital gluten and lecithin the undesirable effects of lipase are stated to be avoided or diminished.
EP 468 731 discloses the use of a bread-improver comprising the enzyme glucose oxidase, optionally in combination with other enzymes such as hydrolases. Lipase is mentioned as one example of such hydrolase.
In both of the above references baking trials are described, in which lipase is added alone without addition of any of the other improving agents described in these references. These baking trials serve the purpose of illustrating the dissatisfactory results obtained by use of lipase alone as compared to the results obtained when lipase is used in admixture with the other improving agents described in these references. In EP 468 731 the lipase used for these trials have not been specified, whereas the lipase used in JP-A 62-285749 is stated to be Talipase, apparently a lipase produced by a species of the genus Rhizopus. In the baking trials disclosed in JP-A 62-285749, the lipase has been used in an amount which corresponds to at least 2240 Lipase Units (LU)/kg of flour.
None of the above-cited references discloses or suggests that the use of lipase in the preparation of dough and/or baked products may be desirable when used alone without any of the other bread-improving or dough-improving agents mentioned in the references.